Fire extinguishing device, system and method for a battery pack

Abstract

The present application relates to the technical field of energy storage, in particular to a fire extinguishing device for a battery pack, which comprises a smoke sensor located in a battery pack box and an explosion-proof pressure relief valve located on the battery pack box, the smoke sensor and the explosion-proof pressure relief valve are arranged opposite to each other; the present application also relates to a fire extinguishing system for a battery pack, which comprises the fire extinguishing device for a battery pack as above, and further comprises a temperature sensor arranged in the battery pack box, a VOC detector, and a controller arranged outside the battery pack box, the controller is used to control pre-warning or start multi-stage fire extinguishing mode to extinguish fire and reduce temperature according to the detection signals of the smoke sensor, the temperature sensor and the VOC detector; the present application also discloses a fire extinguishing method based on the fire extinguishing system for a battery pack as above. The present application has the advantages of more reliable and stable smoke concentration and gas composition detection, more timely detection when the battery pack is abnormal, and safe and efficient use.

Description

Technical Field

[0001] The present invention relates to the field of energy storage technology, and in particular to a fire extinguishing device, system and method for a battery pack. Background Art

[0002] A battery module contains multiple single cells, multiple battery modules are assembled into a battery pack, multiple battery packs are assembled into an energy storage container, and multiple energy storage containers cooperate with energy storage management systems to form an energy storage power station. With the rapid development of energy storage technology, electrochemical energy storage has been increasingly widely used. Currently, the most widely used ones include energy storage battery packs in new energy vehicles, energy storage containers or energy storage power stations in large shopping malls, factories or communities. However, the energy storage safety issues that follow are also receiving more and more attention. Among them, the fire protection technology of battery packs is an important part of battery pack design and production. At present, the deficiencies in the fire protection design of battery packs are: Summary of the Invention

[0003] One of the purposes of the present invention is to provide a fire extinguishing device for a battery pack, so as to achieve more reliable and stable detection of smoke concentration and gas composition and more timely detection when an abnormality occurs in the battery pack.

[0004] A fire extinguishing device for a battery pack includes a smoke sensor located in a battery pack box and an explosion-proof pressure relief valve located on the battery pack box, wherein the smoke sensor and the explosion-proof pressure relief valve are arranged close to and opposite each other.

[0005] The beneficial effects of the present invention are that: the explosion-proof pressure relief valve is arranged on the battery pack case. When the battery pack is in normal working condition, the gas in the battery pack case will flow to the outside through the explosion-proof pressure relief valve, and the smoke sensor is close to the explosion-proof pressure relief valve and faces the explosion-proof pressure relief valve. Therefore, the smoke sensor is just in the flow path of the gas in the battery pack case to the explosion-proof pressure relief valve. Since the gas here has a certain fluidity, compared with other positions in the battery pack case, it can ensure that the real-time detection of the smoke sensor is more reliable and stable, and can better reflect the current gas concentration and composition in the battery pack case as a whole; when an abnormality occurs in the battery pack case, the gas increases sharply, thereby causing a large amount of gas to leak out through the explosion-proof pressure relief valve. In this process, since the smoke sensor is close to the explosion-proof pressure relief valve and faces the explosion-proof pressure relief valve, it can timely detect the increase in gas concentration and the change in gas composition, so that timely countermeasures can be taken to avoid the aggravation of the abnormal situation. Therefore, this design has the effect of more timely and efficient detection.

[0006] A preferred embodiment of the present invention is that it also includes an aerosol fire extinguisher arranged inside the battery pack box near the smoke sensor, a fire-fighting bracket is provided inside the battery pack box, the smoke sensor is detachably mounted on the fire-fighting bracket, and the fire-fighting bracket is detachably mounted on the battery cell end plate.

[0007] The beneficial effect is that: the aerosol fire extinguisher arranged in the battery pack box body can automatically extinguish the fire when the abnormality occurs in the battery pack box body, such as producing an open flame; the smoke sensor is detachably installed on the fire-fighting support, and the detachable structure design is more convenient for maintenance and replacement; and since the smoke sensor is close to and opposite to the explosion-proof pressure relief valve, and the aerosol fire extinguisher is installed close to the smoke sensor, the aerosol fire extinguisher is also designed close to the explosion-proof pressure relief valve, and the advantage of this design is that when the aerosol fire extinguisher is started to extinguish the fire, a large amount of gas (especially combustible gas) accumulated near the explosion-proof pressure relief valve can be directly injected, so that better fire extinguishing effect is achieved.

[0008] The preferred embodiment of the present application is that: the L-shaped connecting support is further provided, the horizontal leg of the connecting support is provided with a first threaded hole, the upper end surface of the cell end plate is provided with a second threaded hole, a threaded bolt is screwed in the first threaded hole and the second threaded hole, a horizontal first connecting column is arranged on the vertical leg of the connecting support, and the upper portion of the fire-fighting support is provided with a strip-shaped hole which is clamped on the first connecting column.

[0009] The beneficial effect is that: by arranging the connecting support and screwing the threaded bolt in the first threaded hole and the second threaded hole, the detachable connection between the connecting support and the cell end plate can be realized, so that the assembly and disassembly are facilitated; by the design that the strip-shaped hole is clamped on the first connecting column of the connecting support, when the assembly is performed, the fire-fighting support with the smoke sensor and the aerosol fire extinguisher installed is directly clamped into the connecting column, so that the quick assembly is realized, and after the strip-shaped hole is clamped into the connecting column, the position of the fire-fighting support can be self-adaptively adjusted according to the requirement.

[0010] The preferred embodiment of the present application is that: the fire-fighting support is hollow at the positions of the smoke sensor and the aerosol fire extinguisher, and the cell end plate is provided with a via hole which is opposite to the hollow position.

[0011] The beneficial effects are: 1. In this solution, the fire-fighting bracket is hollowed out at the smoke sensor and the aerosol fire extinguisher, and the battery end plate is provided with a through-hole relative to the hollowed-out part. On the one hand, the weight of the entire fire-fighting bracket and the battery end plate is reduced, and transportation, installation and disassembly are more convenient; 2. On the other hand, when the interior of the battery pack is in a normal state, the horizontal position of the entire fire-fighting bracket is such that the hollowed-out part does not face the through-hole, or the position is such that the hollowed-out part only partially faces the through-hole. This will neither affect the normal detection of the smoke sensor nor expose the battery cell excessively to affect the dustproof and waterproof effects. When an abnormality occurs inside the battery cell, such as thermal runaway, the internal gas increases sharply. When a large amount of gas flows through the battery cell to the through-hole at the battery cell end plate, When the gas flows through the through hole to the hollow part of the fire-fighting bracket, since the fire-fighting bracket cooperates with the first connecting column of the connecting bracket through the strip hole, it is a floating connection method with adjustable lateral position. Therefore, the rapidly increasing amount of gas can force the entire fire-fighting bracket to produce a slight lateral movement, thereby making the area of ​​the hollow part of the fire-fighting bracket facing the through hole of the battery end plate larger, so that a direct gas flow channel is formed between the inside of each battery cell and the smoke sensor and the explosion-proof pressure relief valve. Compared with other gas flow channels, the gas flow path can be greatly shortened. The gas inside the battery cell can quickly flow to the smoke sensor and the explosion-proof pressure relief valve through the flow channel, making the detection of the smoke sensor faster and more efficient, and the pressure relief of the explosion-proof pressure relief valve more timely, so that fire fighting is also more timely and efficient.

[0012] A preferred embodiment of the present invention is that it further comprises a gas-liquid two-phase nozzle arranged on the battery pack box with the nozzle facing the inner side of the battery box, and the gas-liquid two-phase nozzle is located directly above the explosion-proof pressure relief valve.

[0013] The beneficial effect is that: the present invention further provides a gas-liquid two-phase nozzle. When the battery pack is in a thermal runaway state and an open flame is generated, and the open flame is in a spreading state, simply using an aerosol fire extinguisher may not be able to control the fire. Therefore, the gas-liquid two-phase nozzle can be further automatically controlled to spray the fire extinguishing agent to extinguish the fire. The mist fire extinguishing agent sprayed by the gas-liquid two-phase nozzle fills the entire battery pack body. On the one hand, it has a fire extinguishing effect, and on the other hand, it has a cooling effect. The gas-liquid two-phase nozzle is located directly above the explosion-proof pressure relief valve. Since a large amount of gas is concentrated at the explosion-proof pressure relief valve, the large amount of accumulated gas (especially combustible gas) is concentratedly sprayed by the gas-liquid two-phase nozzle, which can make the fire extinguishing effect better.

[0014] A preferred embodiment of the present invention is that the nozzle of the gas-liquid two-phase nozzle is opposite to the through hole and the hollow part of the fire-fighting bracket.

[0015] The beneficial effect is that when an open flame occurs in the battery pack box and a large amount of gas is generated, the gas flow channel from the inside of the battery cell to the through-holes in the battery cell end plate and the hollow part of the fire-fighting bracket is the shortest, and the accumulated gas is also the most. Therefore, the design of the gas-liquid two-phase nozzle facing the through-holes and the hollow part of the fire-fighting bracket allows the gas-liquid two-phase nozzle to directly spray a large amount of gas. In addition, the sprayed mist fire extinguishing agent can reach the fire site through the shortest flow channel. The combination of these two makes the overall fire extinguishing effect better.

[0016] A second object of the present invention is to provide a fire extinguishing system for a battery pack, including the fire extinguishing device for the battery pack described above. The fire extinguishing system of the battery pack has a smoke sensor for real-time detection, which is more reliable and stable. When thermal runaway occurs and a large amount of gas is generated, the detection is more timely and efficient.

[0017] A preferred embodiment of the fire extinguishing system of the battery pack of the present invention is that it also includes a temperature sensor and a VOC detector arranged in the battery pack case and a controller arranged outside the battery pack case. The controller is used to control the early warning or the initiation of a multi-stage fire extinguishing method to extinguish the fire and reduce the temperature according to the detection signals of the smoke sensor, the temperature sensor and the VOC detector.

[0018] The beneficial effects are: the temperature of each battery cell in the battery pack box is detected in real time through the temperature sensor, the VOC detector monitors in real time whether there is electrolyte leakage in each battery cell in the battery pack box, and the smoke sensor can detect the gas composition and concentration in the battery pack box in real time. Then, the controller uses the detection signals of the smoke sensor, temperature sensor, and VOC detector to intelligently control and issue early warnings or start multi-stage fire extinguishing methods to extinguish fires and reduce temperature, so as to ensure the fire safety of the entire battery pack.

[0019] A third object of the present invention is to provide a method for extinguishing a fire in a battery pack, the method comprising: when the battery pack is in normal working condition or when the gas in the battery pack increases, a large amount of gas is instantly released through an explosion-proof pressure relief valve, and a smoke sensor directly opposite the explosion-proof pressure relief valve is used to sense the gas composition and smoke concentration signal. This method makes the real-time detection of the smoke sensor more reliable and stable, and when thermal runaway occurs and a large amount of gas is generated, the detection is more timely and efficient.

[0020] A preferred embodiment of the fire extinguishing method of the battery pack of the present invention is: temperature signals, gas composition and concentration signals, and VOC leakage are detected in real time by temperature sensors, smoke sensors, and VOC detectors respectively. The controller controls the early warning or the initiation of a multi-stage fire extinguishing method to extinguish the fire and reduce the temperature according to the temperature signals, gas composition and smoke concentration signals, and VOC leakage.

[0021] The beneficial effect is that the control can be automatically and efficiently carried out, multi-level early warning or starting the fire extinguishing device to extinguish the fire and reduce the temperature, so as to ensure the fire extinguishing safety of the whole battery pack. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 It is a structural schematic diagram of the fire extinguishing device of the battery pack of the present application.

[0023] Figure 2 It is a partial structural schematic diagram of the fire extinguishing device of the battery pack of the present application.

[0024] Figure 3 It is a schematic architecture diagram of the fire extinguishing system of the battery pack of the present application.

[0025] Figure 4 It is a structural schematic diagram of the fire extinguishing device of the battery pack of the present application.

[0026] Figure 5 It is a structural schematic diagram of the fire extinguishing device of the battery pack of the present application.

[0027] Figure 6 It is a partial enlarged schematic diagram in example three. DETAILED DESCRIPTION

[0028] The preferred embodiments of the present application are described below in conjunction with the accompanying drawings, and it should be understood that the preferred embodiments described below are only used to explain and describe the present application, and will not limit the protection scope of the present application.

[0029] The terms "first", "second", etc. in the specification, claims, and embodiments of the present application are used to distinguish similar objects, and are not used to describe a specific order or sequence.

[0030] The present application is further described in detail below through the preferred specific embodiments:

[0031] The reference signs in the drawings of the specification include: battery pack box 501, gas-liquid two-phase spray head 502, explosion-proof pressure relief valve 503, aerosol fire extinguisher 504, smoke sensor 505, supporting leg 5051, fire extinguishing support 506, hollow 5061, strip-shaped hole 5062, second connecting column 5063, connecting support 507, first connecting column 5071, bolt 5072, cell end plate 508, via hole 5081.

[0032] As shown in the accompanying drawings Figure 1 , Figure 2As shown: This embodiment discloses a fire extinguishing device for a battery pack, including an aerosol fire extinguisher 504, a gas-liquid two-phase nozzle 502, a smoke sensor 505, an explosion-proof pressure relief valve 503, a fire-fighting bracket 506, a connecting bracket 507 and a battery cell end plate 508, a guide groove 509, and a first electromagnet 5091;

[0033] A spare gas-liquid two-phase nozzle 601 , a mounting seat 602 , a guide rail 603 , a mounting plate 604 , a slider 605 , a second electromagnet 606 , and a magnet 607 .

[0034] In this embodiment, the aerosol fire extinguisher 504, the smoke sensor 505, the fire-fighting bracket 506, the connecting bracket 507 and the battery cell end plate 508 are all arranged in the battery pack case 501, and the gas-liquid two-phase nozzle 502 and the explosion-proof pressure relief valve 503 are both arranged on the battery pack case 501. The nozzle of the gas-liquid two-phase nozzle 502 is facing the inside of the battery case, and the gas-liquid two-phase nozzle 502 is located directly above the explosion-proof pressure relief valve 503. The part of the gas-liquid two-phase nozzle 502 located on the outside of the battery pack case 501 is connected to the gas pipeline at one end and to the liquid pipeline at the other end. Valves that can be automatically opened or closed by a controller are respectively provided on the gas pipeline and the liquid pipeline.

[0035] Specifically, the smoke sensor 505 can be detachably mounted on the fire bracket 506. In this embodiment, a plurality of legs 5051 are arranged on the periphery of the smoke sensor 505, and each leg 5051 is provided with a mounting hole. A second connecting column 5063 is provided at a position corresponding to the mounting hole on the fire bracket 506. The smoke sensor 505 can be quickly disassembled and assembled by snapping the mounting hole into the second connecting column 5063.

[0036] In this embodiment, the fire-fighting bracket 506 can be detachably mounted on the battery cell end plate 508, specifically connected through a connecting bracket 507: In this embodiment, two groups of connecting brackets are respectively arranged on both sides of the upper part of the fire-fighting bracket, and the connecting bracket 507 is L-shaped and can be made of angle steel. A first threaded hole is opened on the horizontal support leg 5051 of the connecting bracket 507, and a second threaded hole is opened on the upper end surface of the battery cell end plate 508. A bolt 5072 is threadedly connected in the first threaded hole and the second threaded hole. A horizontal first connecting column 5071 is provided on the vertical support leg 5051 of the connecting bracket 507, and a strip hole 5062 is opened on the upper part of the fire-fighting bracket 506 to be clamped on the first connecting column 5071.

[0037] In this embodiment, the smoke sensor 505 and the explosion-proof pressure relief valve 503 are arranged close to and opposite each other, the fire-fighting bracket 506 is located at the smoke sensor 505 and the aerosol fire extinguisher 504, and a through hole 5081 is opened on the battery cell end plate 508, which can be opposite to the hollow 5061. The nozzle of the gas-liquid two-phase nozzle 502 is opposite to the through hole 5081 and the hollow 5061 of the fire-fighting bracket 506.

[0038] When the battery pack is in normal working condition, the gas in the battery pack case 501 will flow to the outside through the explosion-proof pressure relief valve 503, and the smoke sensor 505 is close to the explosion-proof pressure relief valve 503 and faces the explosion-proof pressure relief valve 503, so the smoke sensor 505 is just in the flow path of the gas in the battery pack case 501 to the explosion-proof pressure relief valve 503. Since the gas here has a certain fluidity, compared with other positions in the battery pack case 501, it can ensure that the real-time detection of the smoke sensor 505 is more reliable and stable, and can better reflect the current gas concentration and composition in the battery pack case 501 as a whole; when an abnormality occurs in the battery pack case 501, the gas increases sharply, thereby causing a large amount of gas to leak out through the explosion-proof pressure relief valve 503. In this process, since the smoke sensor 505 is close to the explosion-proof pressure relief valve 503 and faces the explosion-proof pressure relief valve 503, it can timely detect the increase in gas concentration and the change in gas composition.

[0039] The fire-fighting bracket 506 is located at the smoke sensor 505 and the aerosol fire extinguisher 504, and the battery end plate 508 is provided with a through hole 5081 relative to the hollow 5061. On the one hand, the weight of the entire fire-fighting bracket 506 and the battery end plate 508 is reduced, and transportation, installation and disassembly are more convenient; on the other hand, when the interior of the battery pack case 501 is in a normal state, the horizontal position of the entire fire-fighting bracket 506 is such that the hollow 5061 does not face the through hole 5081 or the position is such that the hollow 5061 only partially faces the through hole 5081. In this way, the normal detection of the smoke sensor 505 is not affected, and the dustproof and waterproof effects are not affected by excessive exposure of the battery cell. When an abnormality occurs inside the battery cell, such as thermal runaway, the internal gas increases sharply. When a large amount of gas flows through the battery cell to the through hole 5081 on the battery cell end plate 508, and then flows through the through hole 5 When 081 flows to the hollow 5061 of the fire-fighting bracket 506, since the fire-fighting bracket 506 cooperates with the first connecting column 5071 of the connecting bracket 507 through the strip hole 5062, it is a floating connection method with adjustable lateral position. Therefore, a large amount of rapidly increasing gas can force the entire fire-fighting bracket 506 to produce a slight lateral movement, thereby making the area of ​​the hollow 5061 of the fire-fighting bracket 506 facing the through hole 5081 of the battery end plate 508 larger, so that a direct gas flow channel is formed between the inside of each battery cell and the smoke sensor 505 and the explosion-proof pressure relief valve 503. Compared with other gas flow channels, the gas flow path can be greatly shortened. The gas inside the battery cell can quickly flow to the smoke sensor 505 and the explosion-proof pressure relief valve 503 through this flow channel, making the detection of the smoke sensor 505 faster and more efficient, and the pressure relief of the explosion-proof pressure relief valve 503 more timely, so that the fire extinguishing is also more timely and efficient.

[0040] In this embodiment, a third connecting post is provided on the outer side of the battery cell end plate, and a strip-shaped mounting hole is provided on the fire-fighting bracket at a position corresponding to the third connecting post. The fire-fighting bracket is snapped into the third connecting post through the mounting hole. A plurality of legs are also provided on the outer periphery of the aerosol fire extinguisher, each leg having a mounting hole. The mounting hole snaps into the end of the third connecting post during installation. This design of this embodiment not only further supports the fire-fighting bracket through the third connecting post, but also, the cooperation between the strip-shaped mounting hole and the third connecting post allows the fire-fighting bracket to move laterally to expose the via hole of the battery cell end plate when a large amount of gas flows to the fire-fighting bracket without causing the fire-fighting bracket to be fixed. Furthermore, the design of the strip-shaped hole and the strip-shaped mounting hole ensures that the fire-fighting bracket is more stable during lateral movement. The fire-fighting bracket is only connected to the smoke sensor, and is light in weight and compact in size, which does not affect the fine-tuning of the position of the fire-fighting bracket.

[0041] As attached Figure 2As shown, this embodiment also discloses a fire extinguishing system for a battery pack, including the fire extinguishing device of the battery pack as described above, and also including a temperature sensor and a VOC detector arranged in the battery pack box and a controller arranged outside the battery pack box. The controller is used to control the early warning or start the multi-stage fire extinguishing method to extinguish the fire and reduce the temperature according to the detection signals of the smoke sensor, the temperature sensor and the VOC detector.

[0042] In this embodiment, the early warning means that when only the VOC detector detects electrolyte leakage but no open flame is generated and the battery cell temperature does not exceed the normal value, a warning message is issued through the alarm to remind the staff to clean up the leaked electrolyte in time and repair or replace the battery cells or electrical components in the battery pack. The multi-stage fire extinguishing method means that when the temperature sensor detects that the temperature exceeds the normal value and the smoke concentration sensor detects that the gas composition is abnormal, and the concentration exceeds the normal value, it means that an open flame has been generated at this time, and the aerosol fire extinguisher is activated to extinguish the fire. When it is detected that the temperature reaches the warning value and the concentration also reaches the warning value, it means that the fire is still spreading and only one fire extinguishing method can no longer control it well. Therefore, the second-level fire extinguishing method is activated, that is, the gas-liquid two-phase nozzle is automatically controlled to open for further fire extinguishing.

[0043] This embodiment also discloses a fire extinguishing method for a battery pack, which is as follows: when the battery pack is in normal working condition or when the gas in the battery pack increases, a large amount of gas is instantly released through the explosion-proof pressure relief valve, and the gas composition and smoke concentration signal are sensed by a smoke sensor directly opposite the explosion-proof pressure relief valve. Furthermore, the method respectively detects the temperature signal, gas composition and concentration signal, and VOC leakage in real time through a temperature sensor, a smoke sensor, and a VOC detector. The controller controls the early warning or starts a multi-stage fire extinguishing method to extinguish the fire and reduce the temperature according to the temperature signal, gas composition and smoke concentration signal, and VOC leakage.

[0044] Example 2

[0045] The difference between this embodiment and embodiment 1 is that the fire extinguishing device of the battery pack of this embodiment further discloses a connection method between the smoke sensor and the fire-fighting bracket 506. In this embodiment, two guide grooves 509 are provided in the vertical direction on both sides of the hollow 5061 on the fire-fighting bracket. The cross-section of the guide groove 509 is dovetail-shaped, and the lower part of the guide groove extends downward beyond the hollow 5061. A first electromagnet 5091 is provided at the bottom of the guide groove at a position directly opposite to the explosion-proof pressure relief valve, and two sliders (not shown in the figure) that slide with the guide groove are provided on the inner side of the smoke sensor. A metal sheet that can be adsorbed by the first electromagnet 5091 is provided at the bottom of the slider, and the on and off of the first electromagnet 5091 is controlled by a controller provided in the battery pack.

[0046] When the battery pack is operating normally, the electromagnet is energized, attracting the smoke sensor and positioning it directly opposite the explosion-proof pressure relief valve. When a large amount of gas is generated inside the battery pack, the smoke sensor promptly detects the increased smoke concentration, and a large amount of gas is released through the explosion-proof pressure relief valve. If the smoke sensor remains directly opposite the explosion-proof pressure relief valve after a free gas passage has been formed between the explosion-proof pressure relief valve and the exterior of the battery pack, the rapid flow of gas at the explosion-proof pressure relief valve causes the smoke concentration there to be lower than that at other locations in the battery pack, resulting in inaccurate smoke concentration detected by the smoke sensor. Therefore, in this case, the present embodiment can control the electromagnet to be de-energized through the controller, so that it no longer attracts the metal sheet at the bottom of the smoke sensor slider. Under the action of its own gravity, the smoke sensor automatically slides down the guide groove to a position near the bottom of the battery pack, no longer directly facing the explosion-proof pressure relief valve, thereby more accurately detecting the smoke concentration and gas composition.

[0047] This embodiment further discloses a fire extinguishing warning method for a battery pack, and also includes a smoke sensor position adjustment step. When the explosion-proof pressure relief valve releases pressure, the controller controls the electromagnet to cut off power, so that the smoke sensor slides along the guide groove to a position close to the bottom of the battery pack under the action of its own gravity, and is no longer directly opposite the explosion-proof pressure relief valve.

[0048] Example 3

[0049] The present embodiment differs from the first embodiment in that: the present embodiment further includes a spare gas-liquid two-phase nozzle 601, a through-hole is opened on the battery box 501, the spare gas-liquid two-phase nozzle 601 passes through the through-hole horizontally, and one end of the nozzle faces the inside of the battery box 501, a mounting seat 602 is provided on the outside of the battery box 501, a guide rail 603 is provided on the upper part of the mounting seat 602, a mounting plate 604 is provided on the end of the spare gas-liquid two-phase nozzle 601 away from the nozzle, and sliders 605 are provided on both sides of the lower part of the mounting plate 604, the sliders 605 slidably cooperate with the guide rails 603, a second electromagnet 606 is provided on the mounting seat 602 at the end of the guide rail 603 close to the battery box 501, and a magnet 607 that can attract or repel the second electromagnet 606 is provided on the side of the slider 605 close to the battery box 501, and the polarity of the second electromagnet 606 is controlled by the controller according to the temperature collected in the battery box 501 and the temperature collected in the energy storage container.

[0050] The usage scenario and principle of this solution are as follows: In electrochemical energy storage technology, the battery pack is the basic energy storage unit, consisting of multiple groups of battery modules installed inside the battery box. Each group of battery modules contains multiple battery cells arranged in a row. Each battery cell is equipped with a temperature sensor. The temperature inside the battery box is measured by the highest temperature value collected from each battery cell. Multiple battery packs form an energy storage container. The temperature outside the battery box and inside the energy storage container shell is collected by temperature sensors inside the energy storage container. In addition, smoke sensors are also installed inside and outside the battery box.

[0051] Note: In the present invention, in the normal initial state, the second electromagnet is energized so that the polarity of the second electromagnet is different from that of the magnet, thereby adsorbing the magnet, so that the nozzle of the spare gas-liquid two-phase nozzle is directed towards the inside of the battery box, and the spare gas-liquid two-phase nozzle is always connected to the fire protection pipe, and a valve is set on the fire protection pipe.

[0052] The present invention is provided with a backup gas-liquid two-phase nozzle, which has the advantage that when the temperature inside a battery box is too high and the gas concentration is too high, both exceeding the warning value and approaching the dangerous value, the controller can control the valve on the fire protection pipe to open, thereby activating the backup gas-liquid two-phase nozzle to extinguish the fire inside the battery box.

[0053] When the temperature sensor in the energy storage container detects that the temperature in the entire energy storage container is too high, and the smoke sensor in the energy storage container detects that the smoke concentration is too high, indicating that an open flame has occurred and needs to be extinguished, and the temperature and smoke concentration inside a single battery box are not close to the dangerous value, the controller can control the second electromagnet to pass a reverse current, so that the polarity of the second electromagnet and the magnet are the same, thereby repelling each other. In this way, under the action of the repulsive force, the sliders on both sides of the lower part of the mounting plate will slide along the guide rail, thereby driving the spare gas-liquid two-phase nozzle to gradually withdraw from the through-hole of the battery box until the nozzle of the gas-liquid two-phase nozzle is completely located between the outside of the battery box and the outer shell of the energy storage container. Then the controller controls the valve to open and activate the spare gas-liquid two-phase nozzle to extinguish the fire inside the energy storage container. At the same time, after the spare gas-liquid two-phase nozzle withdraws from the through-hole, the through-hole connects the internal space of the battery box and the energy storage container, so that the internal and external gas circulation is better, avoiding the risk of explosion caused by large-scale accumulation of gas due to lack of circulation or poor circulation of gas inside the battery box or the energy storage container. Therefore, this design has more outstanding technical effects.

[0054] The preferred embodiment of the present application is described in detail above in conjunction with the accompanying drawings. Typical well-known structures and common knowledge technologies in the preferred embodiment are not described in detail here. Ordinary technicians in the relevant field can, under the inspiration given by this embodiment, improve and implement the technical solution of the present invention in combination with their own abilities. Some typical well-known structures, well-known methods or common knowledge technologies should not become obstacles for ordinary technicians in the relevant field to implement this application.

[0055] The scope of protection required by this application shall be based on the contents of its claims, and the contents recorded in the invention content, specific implementation methods and drawings in the specification shall be used to interpret the claims.

[0056] Within the technical concept of this application, several modifications may be made to the specific implementation methods of this application, and these modified implementation methods should also be considered to be within the scope of protection of this application.

Claims

1. A fire extinguishing device for a battery pack, characterized in that: The smoke sensor comprises a smoke sensor located in the battery pack case and an explosion-proof pressure relief valve located on the battery pack case. The smoke sensor and the explosion-proof pressure relief valve are arranged close to and directly opposite each other. The smoke sensor is located on the flow path of gas from the battery pack case to the explosion-proof pressure relief valve, and can promptly detect increases in gas concentration and changes in gas composition. It also includes an aerosol fire extinguisher arranged inside the battery pack box near the smoke sensor, a fire bracket is provided in the battery pack box, the smoke sensor is detachably mounted on the fire bracket, and the fire bracket is detachably mounted on the battery cell end plate; It also includes an L-shaped connecting bracket, wherein a first threaded hole is formed on the horizontal leg of the connecting bracket, a second threaded hole is formed on the upper surface of the battery cell end plate, a bolt is threaded into the first threaded hole and the second threaded hole, a horizontal first connecting column is provided on the vertical leg of the connecting bracket, and a strip hole is formed on the upper portion of the fire fighting bracket to be clamped on the first connecting column; The fire-fighting bracket is hollowed out at the smoke sensor and the aerosol fire extinguisher, and a through hole is opened on the end plate of the battery cell that is opposite to the hollowed-out position; When the interior of the battery pack is in a normal state, the horizontal position of the entire fire-fighting bracket is such that the hollow part will not be directly opposite the through-hole or the position is such that the hollow part is only partially opposite the through-hole. When an abnormality occurs inside the battery cell, the internal gas increases sharply. When a large amount of gas flows through the interior of the battery cell to the through-hole at the battery cell end plate, and then flows through the through-hole to the hollow part of the fire-fighting bracket, since the fire-fighting bracket cooperates with the first connecting column of the connecting bracket through the strip hole, it is a floating connection method with adjustable horizontal position. Therefore, the large amount of rapidly increasing gas can force the entire fire-fighting bracket to produce a slight horizontal movement, thereby making the area where the hollow part of the fire-fighting bracket is directly opposite the through-hole of the battery cell end plate larger, so that a direct gas flow channel is formed between the interior of each battery cell and the smoke sensor and the explosion-proof pressure relief valve, and the gas inside the battery cell can quickly flow to the smoke sensor and the explosion-proof pressure relief valve through this flow channel.

2. The fire extinguishing device for a battery pack according to claim 1, characterized in that: It also includes a gas-liquid two-phase nozzle arranged on the battery pack body and with the nozzle facing the inner side of the battery body. The gas-liquid two-phase nozzle is located directly above the explosion-proof pressure relief valve.

3. The fire extinguishing device for a battery pack according to claim 2, characterized in that: The nozzle of the gas-liquid two-phase nozzle is opposite to the through hole and the hollow part of the fire-fighting bracket.

4. A fire extinguishing system for a battery pack, characterized in that: A fire extinguishing device comprising a battery pack as claimed in any one of claims 1 to 3.

5. The fire extinguishing system for a battery pack according to claim 4, characterized in that: It also includes a temperature sensor and a VOC detector arranged inside the battery pack box, and a controller arranged outside the battery pack box. The controller is used to control the early warning or start the multi-stage fire extinguishing method to extinguish the fire and reduce the temperature according to the detection signals of the smoke sensor, temperature sensor and VOC detector.

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